研究表明,目前我国住宅能耗的40%是由门和窗户造成的,窗户能耗为发达国家的2至3倍,所以行业一致认为门窗节能是建筑节能的关键节点。虽然我国目前一些地区开始制订新一轮节能门窗行业标准,但与发达国家相比还很落后。目前国内节能门窗标准最高的北京,K值也与欧洲标准有 Research shows that at present, 40% of the residential energy consumption in our country is caused by doors and windows, and the energy consumption of windows is 2-3 times that of the developed countries. Therefore, the industry believes that the energy saving of windows and doors is the key node of building energy conservation. Although some areas in our country have started to formulate a new round of energy-saving windows and doors industry standards, they are still backward compared with developed countries. Currently the highest standard of energy-efficient windows and doors in Beijing, K value with the European standards